Press operating device



July 16, 1946.

F. A. po| PRESS oPERAT" DEVICE Filed Jan. 17, 1944 INVENTOR. fm2/c p/JBY Patented July 16, 1946 PRESS OPERATING DEVICE Frank A.. Doll,Detroit, Mich., assigner to Link Engineering Co., Detroit, Mich., apartnership composed of Herbert W.

and Frank A. Doll Link, Martha F. Link,

Application January 17, 1944, Serial N o` 518,523.

(Cl. iiD-54.5)

3 Claims.

This invention relates to automatic presses and particularly to anautomaticv press of a combined hydraulic and air-operated type whichproduces rapid movement of the press bed to and from operating position.

When a rapid movement of the press bed was required of hydraulic pressessupplied heretofore in the trade, it was the practice to supply a, pumpcapable of delivering a large volume under high pressure which wasexpensive to manufacture and operate.` For this reason, most of thepresses were furnished without the quick bed operating feature sothat amuch smaller pump at materially reduced cost could be furnished.

It is one object of the present invention to provide an automatic presswith a rapidly operating press bed, the movement of which is producedwithout the use of a hydraulic pump,

It is a further object of the invention to employ equipment which isactuated by air at a relatively low pressure for applying a high staticpressure to the press bed when in operating position and for rapidlyreturning the bed to its initial position.

1t is a still further object of the invention to apply air to a fluid ina reservoir for displacing the i'luid and rapidly raising the bed of thepress to operating position and after disconnecting the reservoir fromthe press to apply the air to a piston of a booster formateriallyincreasing the 31- pressure on the trapped iluid in the pressfor applying an increased pressure on the bed. i It is a still furtherobject of the invention` to include in the electric control circuit Vatime con-1 trol device which controls the duration of operation of thepress and which thereafter operates the control elements to produce therapid return of the bed to its initial position.

Other objects and features of the novelty of the invention will bespecifically pointed out or will become apparent when referring, for abetter understanding of the invention, to the following descriptiontaken in conjunction with the accompanying drawing, wherein Figure 1 isa broken sectional View of a press and the operating and controlmechanism therefor, embodying features of this invention;

Figure 2 is a schematic diagram of the control circuit employed inconnection with the structure illustrated in Fig. l,

A press IU of conventional form embodies a base II having therein acylinder I2 in which a ram or piston I3 projects. The ram or piston issealed within the cylinder by a packing gland I4 Gil oi. conventionalform. The piston supports a bed 55 I5 guided on a plurality of standardst3 and urged downwardly to its lowermost inoperative position by springsI1 provided about the stand-- ard and disposed between the bed and thehead i5 of the press. Die elements I9 and 20 are mounted on the headandbed respectively, being secured in position thereon by suitable bolts 2I.

A tank 22 provides a reservlor for the oil 23, or other liquid employedfor raising the bed I5. The tank is connectedby a Ipassageway 24 througha valve 25 to passageway 26 which is joined` by a conductor 2l to thelower part of the cylinder I2.:

The passageway 26 is joined to a cylinder 28 in which a ram 23 isoperatedby a piston 3| in adouble acting -cylinder 32. The lower partofthe cylinder 32 is :joined to a conductor 33 whichzis also` joined tothe upper part of a cylinder 34 in which the valve 25 operates.

The conductor 33 is joined to a valve housing 35 in which valves 36 and31 operate, The upper part ef the cylinder 3-2 is joined to thewvalvehousing 35 by a conductor 3B `which is joined to a conductor 39 that isattached to the lower part of the cylinder 34. The head 4I of the tank22 is joined by a conductor "42 to a passageway 43 in the valve housing35. The passageway 43 Ais connected to atmosphere through a passageway-The platform I5 oi the press I0 is provided.

with a boss '58 in which a switch operating rod 5l ls adjustably securedby a screw 58. Substantially at the end of the upward movement of thebed l5 the rod 5l contacts a switch operating plunger 59 for operating amicro .switch 6I for breaking the circuit through a con-tact B2 andcompleting the circuit through a contact B3. time controlled relay lillis mounted on the head i8 of the press, or .at some other suitablelocation, for regulating the of operation of the pressA A starter switch'5% and astop switch 65 are also mounted on the press at a pointconvenient to the operator.

When the starter switch @5 is pressed to closed position, relay contactsEli are closed and are maintained closed through the energization of therelay solenoid 68. At the same time current will flow through the pilotcoil 69 of the time control unit 64. This results in the closing of thecontacts 69 which will remain closed through the energization of theunit 64 for an adjustable time period independent of the continuedenergization of the `coil 69, the adjustment being made through thesetting of the lever 17. The closing of the contacts 68 also energizesthe solenoid 53 which operates the valve 36 to the right against thetension of the spring 52. Air is conducted through the passageway 43 andconduit 42 into the tank 22 to apply a pressure of air to the top of theoil or other liquid 23. This forces some of the liquid out of the tankthrough the passageway 24 past the valve 25, which latter is moved tothe bottom cf the cylinder 34 by the passage of the air past the valve31 and through the conduit 33. The liquid iiows through the passageway25 and conduit 21 to the bottom of the cylinder l2, which forces thepiston or ram I3 upwardly until the die elements I9 and 23 are inengagement with each other. As the die elements I9 and 20 are about tocome in contact with each other, the rod 51 engages the plunger 59 ofthe switch 6I to move the contact 62 to open position and to move thecontact 53 into closed position.

The opening of the Contact 32 de-energizes the solenoid 68 and opens therelay contacts 682, which .deenergizes the solenoid 53 and permits thespring 52 to move the valve 35 to the left and exhaust the air in thetank 22 through the passageway l13. The closing of the contact 63energizes the relay solenoid 'I4 which closes the contacts 142 and whichin turn completes a circuit to the solenoid 55. The solenoid 55 operatesthe valve 31 to the left against the tension of the spring E f Thisconnects the conductor 33 tothe atmosphere through a passageway 'l5 andconnects the air from the passageway 43 to the passageway 38 'whichoperates the valve 25 to close off the passageway 26 from the passageway24, thus preventing a flow of liquid from the cylinder I2 to the tank22.

The air also passes into the top portion of the cylinder 32 to move thepiston 3| downwardly. This moves the ram 29 into the cylinder '2t anddisplaces the fluid therein, which build up a pressure in the" cylinderI2, from the passageway 26,`

conduit 2'! and the cylinder 28 to exert increased pressure upon thepiston or ram I3 and increase the pressure between the die elements I9and 20. The pressure that is created in this manner is proportional tothe air pressure times the square of the diameter of the piston 3|divided by the square of the diameter of the ram 29. This ratio can bemade anything desired to produce a desired amount of pressure betweenthe die elements.

After this increased pressure has been applied for a predetermined time,the time control unit 54 operates to open the contacts 69 and itsoperation is interrupted. The opening of the contacts 69 de-energizesthe relay coil i4 which opens the contacts 14 and de-energizes thesolenoid 55.' A spring 54 returns the valve 31 to the right and the airbelow the piston 25 passes through the conductor 39 to atmospherethrough a passageway 18. Air from the passageway e8 passes into theconduit 33 into the lower portion of the cylinder 32 and the upperportion of cylinder 34 to move piston 3l upwardly and the valve 25downwardly to permit the fluid in the cylinder I2 to ow into the tank22. The springs I1 rapidly move the bed I5 of the press toits lowermostposition.

The pressure of air produced by the pump may vary from to 125 pounds sothat the conventional air pressure equipment may be employed to actuatethe press. With the automatic control feature herein provided, thestructure is admirably adaptable for operating presses with heated diesfor curing plastic material as the material is molded into predeterminedform. The regulating valve in the air supply line maintains thepressures constant and the time relay controls the duration ofapplication of the pressure so that the operations are accuratelyrepeated. Other types of presses, such as welding presses, are similarlybeneted by the use of the operating and control mechanism hereinillustrated and described. With this mechanism, hand operated pressesare readily converted to quick acting automatic presses with a minimumof expense.

What is claimed is:

l'. The combination with a press having a bed mov-able into operativeposition, springs urging said bed toward inoperative position, a ram onsaid bed extending in a cylinder for moving said bed to operativeposition, a liquid in said cylinder, a reservoir for said liquidconnected to said cylinder, a valve in said connection, a boosterconnected to said cylinder, an air-actuated piston operating saidbooster, a source of air under pressure, a solenoid valve for directingthe air to the reservoir to move a portion of the liquid into thecylinder to advance the bed to operative position, a second solenoidvalve, means when the bed is substantially in operative position foractuating said solenoid valves to operate the iirst said valve forcutting off the ow of liquid between the cylinder and reservoir, forconnecting the air to the piston of the booster for increasing thepressure exerted by the bed and for removing the pressure of air fromlthe reservoir, anda time control device which reverses the ow of air onthe booster piston and operates the iirst said valve to connect thecylinder to the reservoir to permit the springs to quickly return thebed to its inoperative position.

2. The combination with a press having a bed moved by a ram in acylinder to operative positionfa reservoir for a liquid, a boosterconnected to the cylinder and solenoid operated control valves for asource of air, of a controlv circuit which includes a normally openstarter switch, a relay shunting said switch, a normally closed switchin circuit with said relay, one of said' solenoid valves also being incircuit with said relay and actuated to connect the air supply to thereservoir the liquid in which moves the bed to operative position, anormally open switch actuated to vclosed position when the press ismoved to operative position, which movement also opens said normallyclosed switch and deenergizes said relay and first solenoid valve, asecond solenoid valve actuated by the closing of said second switch toconnect the air to the booster and for disconnecting the cylinder fromthe reservoir, and a third switch for opening the circuit to the secondsolenoid which reverses the flow of air on the booster and connects thecylinder to the reservoir to permit the press to qUCkY'reU-ln UO i11-operative position.

3. The combination with a press having a, bed moved by a ram in acylinder to operative position, a reservoir for a liquid, a boosterconnected to the cylinder and solenoid operated control valves for alsourcel of air, rof a control circuit which includes a normally openstarter switch, a relay shuntim-,r said switch, a normally closed switchin circuit with said relay, one of said solenoid valves also being incircuit with said relay and actuated to connect the air supply to thereservoir the liquid of which moves the bed t0 operative position, a,normally open switch actuated to closed position when the press is movedto operative position, which movement also opens said normally closedswitch and deenergizes said 1 relay and irst solenoid valve, a secondsolenoid 6 valve actuated by the closing of said second switch toconnect the air to the booster and for disconnecting the cylinder fromthe reservoir, a third switch for opening the circuit to the secondsolenoid which reverses the ow of air on the booster and connects thecylinder tothe reservoir to permit the press to quickly return toinoperative position, and a timing device for operating said thirdswitch for controlling the duration of operation of said press. l

FRANK A. DOLL.

